In the transition of an electron in an atom,its kinetic energy changes from $y$ to $y/4$. The change in potential energy $(P.E.)$ will be:

What is the ratio of the wave number of the first line (lowest energy line) of the Balmer series of the $H$ atomic spectrum to the first line of its Brackett series?

In the Bohr model of the atom,when an electron undergoes a transition from $n = 1$ to $n = 3$,the energy absorbed or emitted is ........

What is the kinetic energy of an electron in the second excited state of $He^{+}$? (Energy of an electron in the first shell of $H = -13.6 \ eV$)

In the hydrogen spectrum,the energy during the first Lyman transition is $E = 10.2 \ eV$. The same energy is observed during the second Balmer series transition in which of the following species?

Energy of an electron is given by $E = -2.178 \times 10^{-18} \ J \left( \frac{Z^2}{n^2} \right)$. Wavelength of light required to excite an electron in a hydrogen atom from level $n = 1$ to $n = 2$ will be: